Carthamus yellow colorants, which are flavonoid colorants, are widely used, mainly in the coloring of beverages and other edible products. However, a Carthamus yellow colorant has a distinctive odor that comes from its raw material, safflower (Carthamus tinctorius L.), so when it is used in foods and other products, this odor can sometimes undesirably taint the flavor and taste of these foods, etc.
Consequently, there has long been a need for a Carthamus yellow colorant formulation that can be added to foods and so forth and an aroma component therein has been reduced to the point that the distinctive odor of safflower is undetectable, and various purification methods have been examined up to now. Methods that have been proposed for refining a Carthamus yellow colorant include a method in which a Carthamus yellow colorant aqueous solution is treated with an ion exchange resin (Japanese Patent Un-examined Publication H4-214767), a method in which a water-soluble food coloring is extracted with an organic solvent or supercritical carbon dioxide (Japanese Patent Examined Publication H4-48420), and a method in which a water-soluble natural colorant is brought into contact with an adsorption resin and subcritical or supercritical carbon dioxide (Japanese Patent Un-examined Publication H10-36701).
However, few methods have been disclosed for removing the distinctive odor of a Carthamus yellow colorant. A Carthamus yellow colorant formulation prepared by one of the above refining treatments still has a strong and distinctive odor that comes from the petals of safflower, and such a formulation cannot be considered to have solved the above problems.
Also, conventional Carthamus yellow colorant formulations have been indicated as having a so-called “return smell,” that is, the odor gradually becomes stronger over time due to the effects of heat, light, and so forth during storage, and this problem of “return smell” has yet to be resolved with the various refining treatments discussed above.